It is common knowledge that burnout is built up in a period of repeated stressors, to which the body reacts with a heightened level of physiological activity. The build-up especially occurs if this enhanced physiological activity does not get adequately restored in a subsequent period of rest or relaxation. In a review paper Bruce McEwen describes the effects of stress in health and disease (McEwen: “Central effects of stress hormones in health and disease: Understanding the protective and damaging effects of stress and stress mediators”, in European J. of Pharmacology 583 (2008), p. 174-185). He describes stress as having two different sides: On the one hand, the body responds to almost any sudden, unexpected event by increasing heart rate (HR) and blood pressure (BP), helping the individual to cope with the situation; on the other hand, chronic elevation of these same parameters—e.g. chronically increased heart rate and blood pressure—produce chronic wear and tear on the cardiovascular system.
The term “allostasis” has been introduced by Sterling and Eyer to refer to the active process by which the body responds to daily events and maintains homeostasis (see “Allostasis: a new paradigm to explain arousal pathology”, In Fisher, S., Reason, J. (Eds.). Handbook of Life Stress, Cognition and Health. John Wiley & Sons, New York (1988), p. 629-649). In an earlier paper McEwen introduced the terms allostatic load and allostatic overload to refer to the wear and tear that results from either too much stress or from inefficient management of allostasis, e.g. not turning off the response when it is no longer needed (Mc Ewen: “Protective and damaging effects of stress mediators”, New England J. Med 338 (1998), p. 171-179).
It is clear that heart rate is a parameter that reflects this process of activation and restoration. And indeed, increased heart rate has been found to be correlated with the presence of burnout (see e.g. Boneva et al.: “Higher heart rate and reduced heart rate variability persist during sleep in chronic fatigue syndrome a population-based study”, Autonomic Neuroscience: Basic and Clinical 137 (2007) 94-101).
The major restorative factor that most of us have in our lives is our vacation period. And also weekends usually have a restorative effect on our physiological activation. That is why we expect heart rate to be lower at the end of a vacation (unless it was an extreme-sports one), or at the end of the weekend. Within the period of the week, for most of us our working time slot, the major restorative factor is our night's sleep. Therefore, we also expect heart rate to have decreased gradually during the night and be at a minimum at wake-up in the morning (see van Eekelen et al.: “Circadian variation in base rate measures of cardiac autonomic activity”, Eur J Appl Physiol (2004) 93: 39-46). At the end of the weekend, and at the end of the vacation, the morning heart rate might be slightly lower than is usual at wake-up during week days. But, if the process of sleep restoration is starting to become less adequate, the heart rate at wake-up (on week days as well as on weekends) will start to rise above the usual values. This is an indication that the body needs extra restorative conditions, or less stress—otherwise the consequences are a long-lasting deteriorating effect on one's health (e.g. burnout).
Burnout is a problem most of us would want to prevent, since it is not pleasurable and has significant impact on our daily behavior and activity. But also the employers would like to prevent their employees from developing a burnout, because it is bad for the overall productivity as well as for the company's image. Nevertheless, many of us do slip into it, with a prevalence as high as 5% in the Netherlands, and higher numbers estimated for Asia and the USA.
Preventing burnout is difficult, however, because many people are not inclined anymore to pay attention to their bodily signals that warn them. It is common not to notice these bodily signals, which allows us to maintain a pleasant, but unsafe, unawareness of the upcoming problems. People who have developed a burnout on the other hand usually state that afterwards they are much more capable of recognizing their body signals indicating a developing overload again.
In WO 2009/057033 A2 a system is proposed that provides a human low battery warning that indicates to the user in a very simple way that he/she should change his/her behavior by sleeping more, eating better or relaxing more to prevent the user from being over-stressed or getting a burnout. This simple warning can help people to take a break when they need it and to make sure that their “human battery” does not get empty.
One of the problems many prior art documents are focusing on is a meaningful way how to measure the vital signs (e.g. HR) of the user. If a user, for example, has to actively measure his/her HR on a daily basis, his/her consciousness might falsify the measurement, as the user's awareness is directly drawn to the measurement procedure and they might think about it or even prepare themself to it. Another problem is that users might forget to measure their vital signs, especially if this is required to be done on a daily basis. Some devices might, due to their obtrusiveness, also feel uncomfortable for the users. Since people travelling a lot for their work are exposed to many stressors and have a higher risk of developing a burnout, the mobility and practicability of such stress-measuring systems and devices is also an issue.